Preparing CEPH for main inclusion

CEPH has become a first class object and block storage mechanism, and has integration hooks for key pieces of Ubuntu Cloud Infrastructure. Especially interesting is CEPH-RBD for storing kvm block devices on the scalable CEPH block store, and the Hadoop HDFS shim to replace HDFS with CEPH in hadoop clusters.

No formal spec needed IMO, this is just a pile of straight forward actions.

* gceph is not reasonable to be in main (upstream doesnt want to support)

Today rbd is loaded loaded at runtime

- MIR librbd and librados for qemu/kvm
- compile qemu-kvm with ceph (rbd, rados) block device support, see:
- https://launchpad.net/~kirkland/+archive/virt/+packages
- MIR all of ceph for hosting ceph
- include latest libvirt rbd support (for rbd authentication)
- Existing Openstack Support
- Nova since cactus can use CEPH for block
- Diablo added glance support for CEPH for image storage
- Dreamhost using mainline BTRFS and debian kernel for current deployment
- Dreamhost launching at scale in a few "weeks"
- CEPH is an independent business unit under Dreamhost
- Dreamhost using fastcgi + apache for rados gateway (can use nginx, too)

Dependencies:
modfast-cgi
Concerns;
- Upstream makes a release every 2 weeks
- No stable release branches upstream
- Limited deployment outside Dreamhost
- unencrypted over the wire
- apps can implement security on top of it
- IPv6 is supported
Additional Opportunities:
- Integrate tightly with OpenStack in packaging
- Add support for ceph in juju openstack charms
- BTRFS ideal, XFS also working well, ext4 missing "large xattr" support
- Upstream asserts that CEPH is under heavy development (cmdline programs remind user at every execution)
- in the openstack use case, for kvm, there is no need for kernel code at all
- if we want to support xen, it would require using the block device kernel code for rdb
Support Targets:
- RBD